Wireless receiving system



' Sept. 2, 1930. w. T. Ll-:wls `l 1,774,834

WIRELESS RECEIVING SYSTEM Filed Aug. 6. 1927 2 Sheets-Sheet l www Y: r F95 ifi.

f @w E Sept. 2, 1930. w'. r. Lewis 1,774,834

nnsmass nscarvnm ssrs Filed Aug. 6. 1927 2 Sheets-Sheet lhlli-Lllllhhtji.

PatentedvSeptvZv, y il l l iV rieures l PAT fr :a Fics WILLIAM TUENOE LEwIs, OE RACINE, WISCONSIN i WIRELESS RECEIVING SYSTEM' Y Application inea August-c, 1927. serial N0..21"1,12o.1g p

This kinvention relates to Vawireless receiv- A further'cbject is to provide a radio ref ing system.V j ceiving'r system inl whichthe antenna effect In. wireless receiving systems, it has been will not disturb any ofthe tuningcondensersv heretofore proposedto reflex the audio freso thatv antennae of different lengths may be 5 quency energy through the tuned radio fre- Connected upto the sets without any change .55k

quency. tubes. These systemsl however have inthe setting. 1 n i. i' not provenwholly satisfactory for they dis- Embodimentsv of the invention are shown turb the sharply timed Circuits ofthe tubes` in the accompanying drawings in which:` i y and prevent an efficient functioning ofthe Figure1isa viewsliowing diagrammati- '10 system.V `In additionto this, the tuned -cir cally one form that the invention vmay take in 60 cuitsof the several tubes cause Vra'iliation. to which the audio'frequency energygis refleXed L occur from the antenna with consequent disthrough the. untuned tubes which are selecturbance to other receiving sets.l f tively picked out .n This invention is designed to L overcom kFigure 2 isv a diagrammatic rView showing a i5 the defects noted above and objects of such further form ofthe inventioninfwhichrthe i65 n invention arek to provide .a` novel 'form of unt'uned tubes are used Vfor reiiexing. the L radio receiving system in which the tuned audio frequency energy, butinwhich the reiadiofrequency circuitsof theitubesare not flexing is-done in an" inverse manner. disturbed, but in Vwhich untuned tubes are [Referring tovFigurel, it will be'seen thatl fc placed between the tuned radio frequency 'theitub'es are numberedltoS inclusive. The '(0 tubes and theaudio frequencyv energy reantenna-9 isiconnectedl through the coil 1,0 to i iexed through the untuned tubes without dis#V the ground 11 and, opposite ends ofthe coil turbing any of the tuned Circuits. 1 c Y l0. are connected to the grid' l2 and the nega- Further Yobjectsare to provide'a radio retive side 'of' thefilament 13 of the first tube *'25 ceiving system in which the untuned tubes l. The-plate 14`of this tube -is connected to H5 j i 30 'as radio frequency amplifiers as thetubes 1'7isbridged across the `'coil 16.k .E

serve not only as radio'frequenc/yv amplifiers, the primary 15Jof a radio frequency transbut also as audiofrequency amplifiers. It is .former Awhose secondary 16 has its ends conwell known that the tubes with theiry unf nectedto the grid and filament ofthe tube tuned circuits do not functionV aseificiently numbered 2. A; variable tuningy condenser V8o with timed circuits. However,"this inven- The plate'Qf-the tube 2 is connected tothe tion utilizes such amplification as occursfor `primary a 18 of a second vradio vfrequency the radio frequency, but also loads these untransformer whose secondary 19 has one end timed tubes up with the audio frequencyerr connected to .theV grid of the ytube 3. Ifde- A35 ergy so as to secure a greater over-all effisired, the coil 18 may be used kas a radio g5 ceiicy than has hereOfOl been pOSSbleWthfrequency choke for the plate -circuit ofthe out increasing the number of tubes. In other *tube 2* and a condenser 20 may be connected words, objects of this'invention are to pr.- between the plate of-the .tube Zand the grid vide a radio receiving system in which lthe of the tube 3. If desired, thexcondenser and 140 untuned tubes are selectively picked out for transformer may bothbe used 'as shownin 90 the audio frequency amplification without the figure.vv Y. e Y disturbing the tuned tubes, although the uri- -The other end of the secondary 19 of the vtuned tubes are also employed in the capacity radio frequency transformer is connected to of radio frequency amplifiers. one side of the secondary 21 of an audio fre- 45 Further objects are to provide a radio requency transformer. fTlie other side of this 95L ceiving system having the characteristics audio frequency transformer secondary is enumerated above in which there lis no radiaconnectedvto the'negative side of the filament tion from the antenna althoughjth'e-system of thetube'3,as indicated. Also, itis to be4 may be sharply tuned and may .worlrat its notedy that a radio frequency bypass con- 50 maximum efficiency. l denser 22 is bridged across thesecondary 21 Y100 Y -of the `audio frequency transformer. The

primary 23 of the transformer is provided with a bridging condenser 24 which may bek of largev capacity and the primary is connected in a manner hereinafter described for transmitting audio frequencyenergy to the tube 3 from another portion of the system.

vIt is to be noted that the grid circuit of the tube 3`is u-ntuned. The tube 3 has its plate connectedthrough the primary 25of a radio frequency Atransformer and throughthe pri- .mary 2G of an audiol frequency transformer to the point 27 of the B battery indicated by the referencek character Bin the ligure. Pref'- erably, a condenser 28 is bridged across the terminals of theprimary 26.y The secondary 29 ofthe radio frequency transformer as sociate'd withV the plate of the tube 3 is connected at one end to the grid of the tube 4 and at its other end to thefilament of such tube.vk It is bridged byrmeans of a variable 'condenser 30 so that the grid circuit of the tube 4 kmay be tuned.

The plateof the tube 4 is connected through the primary`31=ofV a radio frequency transformer toi the point 27 of the B battery. Preferably,amainbusbar 32 is employed, as shownin Figure 1, and connected to the plate circuit'of the several amplifying tubes, as will appear as the description proceeds. y'The secondary 33 of theilast described radio frequency transformer is connected tov the grid ofthe tube- 5. If desired, a condenser 34 similar .to the condenser 2O may be valso employed. rIhis condenser as well asthe i' busbar 37". The plate of the tube 5 is connected through the primary 38 ofaradio frequency `transfo'rrner -to one end of the primary 39 of ani-audio frequency transformer.'

The other endof thefprimary 39 is connected to the busbar 32' and from thence to the point 27 of 'the B battery. Preferably, a bypass condenser 4() is provided between the terminal of the audio frequency primary 39 and the busbar-32 in order to bypass radio frenquency energy. The last described radio frequencytransformer has its secondary 41 connected to the filament and grid of the-tube 6. Further, this secondary is connected toy tliepvariable tuning condenser 42 so that the grid circuit of thetube 6 may be tuned. The plate of the tube is connected to one end of the primary 43 of a radio frequency transformer and the secondary 44 of such transformer is connected to the grid and fila ment of the detector tube 7. The usual grid condenser and leak is employed in this circuit. rlhe secondary 44 is bridged by means of the variable tuning condenser 45. rlhe plate of the detector tube 7 is connected by ine-(ns of the conductor 46 with one side of the primary 23 of the first described audio frequency transformer. rthe other side of the primary is connected to the point 47 of the B batteryv so as to secure the requisite voltage for thel detector tube. lt is to be noted that the primary 39 of the last audio frequency transformer is associated with the secondary 48 of such transformer, and such secondary is connected to the grid of the power tube 8 at one end. rlhe other end of the secondary is connected to the point 49 of the biasing battery or C battery indicated by the letter C in the ligure. rlhe positive side 50 of such battery is connected to the negative filament busbar 37. Y

The plate of the power tube 8 is connected to one side of an audio frequency choke coil 51, the other side of such coil being connected to the vpoint 52 of the B battery to secure the voltage for the plate circuit of the power tube. A stopping condenser and a translating device indicated by the reference characters 53 and 54, respectively, are Yconnected to opposite ends ofthe audio frequency cholre coil 51. The translating ldevices may obviously be a telephone receiver' or a loud. speaker, or any other suitabledevice. rthe purpose of the condenser r53 is to prevent the impressing of the high voltage upon the terminals of the translating device and to avoid the necessity of continuously passing the plate current therethrough.

It is to be noted that a suitable filament battery as indicated by the reference character A is employed and a single rheostat 55 maybe used for simultaneously controlling all of the filaments.

vrEhe condensers 17, 30, 42, and 45 are tuned sharply to the desired wave length and it is apparent that these condensers may be either simultaneously tuned or individually tuned. In addition to this, it is to be noted that any type of coupling may be employed between the tubes. Also, it is apparent that instead of using radio frequency transformers between the tubes 2 and 3 and the tubes 4 and 5, that the coils 18 and 31 may be used as radio frequency chokes and the condensers 2O and 34 may be used to pass the amplified radio frequency energy to the succeeding tube. l? irther. if this is done, it may be found desii'able to omit the coils 19 and 33 although their use is preferred.

ln using the system, it is apparent that the antenna effect does not influence any of the tuning condensers and consequently antennae vio A i diraient lengths maybe connected te? different sets With out disturbing their tui'iing.V

`When the system is in operation, til/1era`Y dio frequency energy ainpliiiedbylthe'tube l is passed to the'tune'd lcircuit'for the tube '2 and is again amplified and passedto the'un.-

tuned circuit of the tubeA 3.' 'From' thence',`

it passes to the tuned circuitfoftl'ie tubet and Y from'thence to the untunedcir'cuit of the 'tube `5.y The'tube 5 passes they radio frequencyenergy to tlietuned'cilcuitof the tube 6 andato the grid circuit of the detector tube 7.` This Y grid circuit mayfbe either tuned Vor untuniedvr quency `energy-is passed through the primary 23 of the first audioy frequency transformer.

The secondary of the transformerv supplies' audio frequency energy to the ,grid of ithe tiibe 5 and -frointhe plate of s uch tube passes through theV primary l39 of the last audio fretube 3. t is to be noted that the'plate circuit of the tube 3 includes the'primary 26;.o'f the'. next audio frequency transformer and, 1 consequently, thel audio frequency., energy is 'passed through ksuch primary". y,From the secondary .35 of this transformer the audio frequency energy passed to the grid ofthe quencytransfformer. 1 TheY secondary 48 i of It is apparent fromjtrhe,v description and the l eiiiciencyof t-he systefmis very much increased l suchtransformer isA connected `to the vgrid Vof.

fthe power tube. p

drawings that thek untunedftubes are'picked out selectively 'and the audio frequency en! ergy is passed'only through such tubes. t is not passed through.thejtunedtubes and con` sequently does not disturb such'tubes. v tvis apparent therefore thattheover-.lall

as the untuned tubes,-although'servin g` as raldio frequency amplifiers, vare empioyedin la v Vdouble capacity and-'are alsoused asv audio' Vfrequency. amplifiers. It is apparent that' the untuned tubes are not so eiiicientas radio` fre'- quency amplifiers asthe tuned tubes, butthey are. nevertheless alsoy called upon to actas audio frequency amplifiers. The consequence lof thisis that the over-all eficencyof the system is very 'greatly increased` Without' increasing the numberof tubes. In addition to this, there is'no possible chance of radiation from the antenna.

lIn Ythe form of the; .invention V shown inv f In this form of the invention", the tube 'lhas its grid and filament connected to opposite ends of the coil 1,0 in theantenna circuit.' its plate is connectedthrougli thesecondary 56 of a radio frequency transformer to the' positive busbar 57 connected tothe point 58 ofthe ondary 67 of such transformer'being connect- "ed to the grid and filament of the tube `4, and

B` battery.'l 4The secondary 159 k'oftheradio fre'quencyptran'sformer'iis connected to the filament and grid ofthe tube 2 andv is bridged bythe variable timing condenser 60.- The plate of the tube 2 is connected through the radioy frequency vchokeV coil y6l to the: busbar 57 Acondenser 62.. is connected from the 4'plate of thetube 2 yto the grid of the tube 3 and also it is to be'noted that the secondary Y 636i?l anaudio frequency transformer has one other end isconnected-through a biasing batltery or auxiliary C battery'64 to the filament of the `tube 13..; The primary vof thisaudio` frequency"-'transformer is 1 indicated the f reference character 65 and vitsv connections A y 3 Vifl -v70jl L yend connected tothe grid of the tube 3. Its j .Will'bedescribed hereinafter. `Thle tube3 has' its plate connected through the secondary 66, c

of aV radio frequency"transformer,,thevsecf bridged by acondenser 67'.. y

The plate ofthe tube 4 is connected through a radio frequency choke coil;68 to the busbar` '57.v A condenser 69 is connected from the i plate lof the tubettojthe grid fof the tube 5. Further, it isftob'e notedthat thesecondary I K 70.of 'anfaudiofrequency transformer is c'on-v j nected to thegri'd of the tube 5andtothe neg; j ative "side cfa secondauXilifaryC battery 7l.

hereinafter.

'The ,other side vof the@ battery isiconnected' tothe lfilament ofthe tube 5 f AThe connections 'of-fthe, primary :72 ofthis last mentioned' audio frequencytransformer vvillbel described 1406' l The plate of the-tube' is connectedktq one r1;,

:I side ofthe primary7 3 of ara'dio frequencyV transformer. Theother side of the primary 73 isjfco nnected by means'of a conductor 74%l v to one side of the primary ofthe first audio frequencytransformer." vThe other side/of suchprimary 65 is connected to thebusbar 57.l

A bypassingV condenser y7 5 is connected across the'terminal's of the primary 65 inorder to i -'l ondary 76 ofthe radioffrequency transbypassradioi frequency energy.vv4 The' secformer between the tubes 5and 6 has itsterminals connected to theY grid Vand' filament-of the tube 6.k This secondary. is also bridged' -tube'6 is' connectedthrough the primary j78 by ja timing condenser 77. The plate of the of a radio. frequency transformer to the bus-` i bar 57. The secondary 79 of such transformery is connected tothe grid and filament 'of 1 theV detector tube 7, a suitable grid condenser rand leak being employed, as indicated. The

plate ofthe tube 71 is connected by means of f conductor 8OntoV one side of the primary 7 2 of L the second mentioned audio frequency trans-v former. The other side of thisA primaryl is connected to the point y81 ofthe Bpbattery to securethe requisite lvolta-ge for the detector tube.V Preferably., 'a relatively large" condenserf82 is bridgedacross the terminals of f "the primary 7 2, as indicated. 1

soyf

side of the primary 84 of the last audio frequency transformer'. The other side of this primary is connected to the busbar 57. rrlChe secondary 85 of this last audio frequencl vtransformer is connected to the grid and filament of the power tube `8, a suitable biasing` battery, indicated by thereference character C being interposed in this circuit.r

' v Theplateof the'tube 8 isconnected through an audio frequency choke coil 86 to the point 87 of thefB battery to secure the requisite voltage for the tube 8. `The terminals ofthe coil 86 are also Vconnected through a suitable stoppingL condenserBS to the telephone receiver, orr` loud speaker or other translating device 89 as previously described.

In operation, theradio frequency energy i is passed successively through `the tubes l, 2,

frequency energy y through the Vprimary 72 of the audio freso 3, 4, `5, and 6. 'From the tube 6, this amplifiedxradio frequency energy' is passed to the grid ircuit of the detector tube 7. The audio from the tube `7 passes quency :transformer previously described.

Thesecondary -70 of this audio frequency transformer passes audio frequencyenergy to Y the grid'ofthe tube 5, the .biasing battery 71 holding the negative charge of the grid of the vrtube 5 at the desired point. rlhe plate circuit Vofthe tube includes the primaryy v65 of the first described audio frequency transformer. The secondary v.of thisy transformer Vpasses audio frequency to the grid of the tube 3.

.A C battery 64, similaryto the battery 7l, is

employed for kthis tube.Ak The plate circuit of the ltube 3 includes the 'primary Sil of 'the last audio frequency transformer.

Further., it isto be noted that this primary isbridged by a bypass condenser 90 in order to pass-.radio frequency energyto the busbar 57. The secondary 85 of thelast audio Vfrequency transformer suppliesthe grid circuit of the power tube.

It will be seen that in this form yof the invention the audio frequency energy from the detectoris first passed to the tube, from rthence/to the tube 3, and thereafter 4to the power tube 8. In each case, the audio fre- `quency Aeifiergy is selectively passed only through the untuned tubes. lt is not 'passed through the grid oircuitsof the tuned tubes.

l Consequently, the tuned ktubes are not loaded `up with the audio frequency energy in either Vform of the invention and the untuned tubes alone are calledvupon to amplify the audio frequency energy in addition to. some ampliipication' of the radio frequency energy passed through these tubes. The net result of this y method of handling theaudio and radio fre* Vquency energy, in the two forms of the inf vention disclosed, is that thetuniiig is maintained sharp and the tuned circuits are not called upon to carry audio frequency energy. The tubes associated with the untuned circuits alone carry the audio frequency energy.

ln addition to this, inasmuch as die untuned tubes are interposed between the tuned tubes, it is apparent that radiation from the autenna is prevented. The system as a whole, cannotJ be tirown into oscillation during receiving and consequently, the antenna will not radiate. y

lt isapparent therefore that a highly edicient and novel mode of radio reception has been provided by ,this invention andA oner which will not disturb other nearby receiving systems.

lt is also apparent from an examination of Figures l and 2, that relatively simple connections may be employed and a small number of busbars. Further than this, only a small numberk of terminals are required for the entire set. y

ln addition to this, a very accurate tuning can be secured with the utmost facility with either form of the invention.

'lt is to be distinctly understood that although vacuum tubes having input and output circuits have been shown, that obviously other forms of amplifying devices having input and output circuits could be used without departing from the spirit of this invention.

lt is to be distinctly understood that otherl modes of coupling the tubes may be employed and other changes may be made without devparting from ythe spirit of this invention and therefore it is intended that the description anddrawing-s be interpreted as illustrative rather than limiting as the scope of the invention is to be determined only as set forth hereinafter in the appended claims.

l claim:

1. In a radio receiving system, the combination of a'plurality of tuned circuits including amplifying devices and a plurality of untuned circuits including amplifying devices, and means for reflexng audio frequency energy only' through the amplifying devices associated with the untuned circuits.

2. ln a radio receiving system, the combination of a series of alternately tuned and untuned circuits including amplifying devices, and means for reflexing audio frequency energy through the amplifying devices associated with thev untuned circuits.`v

3. ln a radio receiving system, the combination of a plurality of vacuum tubes having coupled grid and plate circuits, the grid circuits of certain of said tubes being tuned and the grid circuits of other of said tubes being untuned, certain of said uiituned circuits bein g located between timed circuits, and means for reflexing audio frequency energy through the tubes having unt-uned grid circuits.

lln

4. A radio receiving system comprising `transformer having its primary connected toy means for collecting'radio frequency energy, a. vacuum tube having anuntuned grid circuit c connected to said collectingmeans, a` second vacuum tube having a tuned grid circuit sup,-V plied from said. first tube, a third ,vacuum tube having an untuiied grid circuit supplied@ from saidsecond tube,:a detector` tube, means coupling the output of said detector ftube Vvvith said third tube, anda translatingdevice operated fromsaid tubes.-

5. A radio receivingy 'system' comprising means vfor collectingk radio frequency energy, a vacuum tube having an untunedgrid circuit associated With said collecting means, a second vacuum tube having a tuned grid circuitv "supplied from said firsttube, a third vacuumuum tube having a tuned tube having an untuned grid circuit supplied from said second tube, a detector tube, vmeans coupling the output of said detector tube with' said third tube, and means for reflexi'ng audio f v f frequency energy'through one of the tubes having an unt'uned grid-circuit. l 1

6; In a radio receiving system, the 'combination of a pluralityof amplifying devices connected incascade, said devices having input and outputcircuits", 'a plurality of said input the .output circuit of said detector and having its secondary connectedtmthe'gridfand'laf ment of said"third tube,va sfecond'audio'frequency transformer having its primary conv nected in circuit With the` plate of'saidthird y tube andhavingits secondary connected to n the plate and filament ofsa'id` fifth tube, `a third audio frequency'transforinerhaving its primary connectedin circuitvvith the plate of said fthv tube,an eighth vacuum tube having its lilament and grid'connected to the secondary of said third audio frequency trans-l former, i and a translating device supplied from the plate of said. eighth tube. Y c In testimony whereof, thesignature ofthe inventor is affixed heret WILLIAM TURNOR,Liivvis.l

circuits being tuned and a` plurality of said j input circuitsl being untuned, one of said dev vices being a detecting "device, the output f circuit of said detecting device being reflexed through the untuned input circuits of certainA 7. A radio receiving system (comprising. means for collecting radio frequency energy,- la lvacuum tube having a grid circuit connected to said collecting means, asecond vacuum-tube having a 'tuned ygrid circuit supplied from said first mentioned tube, a third'V vacuum tube havingY an untunedv grid circuitl supplied from said secondv vacuum tube, an audio frequency transformerV` having .its secondary connected to ,the .gridv andy filament of the third tube, a detector'having 'its inputvcircuit controlled from the outputcircuit of said thirdtu'b'e, said detector having its output circuit connectedV in series With the primaryof said audio frequency transformer,

output circuit l'of said third tube. 8,. A radio` receiving system kcomprising means for collecting radio frequency energy,

and a translatingPv device controlled from the "a vacuum tube havingits grid circuit` connected to said collecting means,l a vsecond vacuumtube having atuned grid circuit supplied from said first mentioned tube,.a third c vacuum tube having an untuned grid circuit supplied from said second tube, a fourthk vacgrid circuit supplied from said third tube, a fifth vacuum tube having an untuned grid circuit Vsupplied from said fourth tube, a sixth vacuum tube having Y izo ` a tuned grid circuit supplied from said fifth' i" tube, a detector having a grid circuit supplied i Y' from `said sixthA tube, an audio frequency. 

